Parameterization of Pulses from a Particle Detector Using a Flash ADC

62 Pages·2014·2.5 MB·English

IT 14 069
Examensarbete 30 hp
December 2014
Parameterization of Pulses from
a Particle Detector Using a Flash
ADC
Yunyi Huang
Institutionen för informationsteknologi
Department of Information Technology

Abstract
Parameterization of Pulses from a Particle Detector
Using a Flash ADC
Yunyi Huang
Teknisk- naturvetenskaplig fakultet
UTH-enheten With the deep exploration of particle physics, particle accelerators, detection
methods, data recording and processing, and application of computing technology are
Besöksadress: continuously developing. It has not only brought progress in particle physics, but also
Ångströmlaboratoriet
promoted the development of the Science and Technology. The main focus of this
Lägerhyddsvägen 1
Hus 4, Plan 0 thesis is data recording and processing. It provides a calibration method for pulses
processed by ADCs. It uses some existing filters to achieve the accurate parameters
Postadress: of pulses and existing concept to do the comparison among filters. The FPGA
Box 536
implementation scheme is also discussed in the paper.
751 21 Uppsala
Telefon: Key words: Particle detector; FPGA; Pulse parameters.
018 – 471 30 03
Telefax:
018 – 471 30 00
Hemsida:
http://www.teknat.uu.se/student
Handledare: Pawel Marciniewski
Ämnesgranskare: Leif Gustafsson
Examinator: Philipp Rümmer
IT 14 069
Tryckt av: Reprocentralen ITC

Acknowledgements
First I would like to thank my supervisor Pawel Marciniewski for his valued
support and encouragement in the past one year.
I thank Leif Gustafsson who agreed to review my master thesis and provided
precious views and suggestions for this paper.
Finally, I should thank my mother for her love and providing me with the
support needed in order to continually push myself to succeed.

Contents
1. Introduction ........................................................................................... 1
1.1 Aim ....................................................................................................... 3
2. Structure................................................................................................. 5
2.1 Hardware .............................................................................................. 5
2.1.1 ADC .............................................................................................. 5
2.1.2 FPGA ............................................................................................ 6
2.1.3 Board Layout ................................................................................ 6
2.2 Software ............................................................................................... 7
2.2.1 ISE® Design Suite ........................................................................ 7
2.2.2 The ChipScope Pro™ tool ............................................................ 8
2.3 System Implementation Structure ...................................................... 10
3. Signal Pre-Process ............................................................................... 13
3.1 Analog to Digital Conversion............................................................. 13
3.2 Serial data received in the FPGA ....................................................... 15
3.3 IDELAY and IDELAYCTRL ............................................................ 18
3.4 Data Deserialization ........................................................................... 20
3.5 Checksum & Aligning ........................................................................ 22
3.6 Calibration .......................................................................................... 22
4. Filtering ............................................................................................... 27
4.1 Moving Window Deconvolution ........................................................ 27
4.2 Finite Impulse Response Filter ........................................................... 30
4.3 Moving Average ................................................................................. 30
5. Parameterization .................................................................................. 33
5.1 Pulse parameter .................................................................................. 33
5.2 Baseline .............................................................................................. 34
5.3 Threshold ............................................................................................ 35
5.4 Amplitude ........................................................................................... 37
5.5 Rise and Fall Time ............................................................................. 37
5.6 Pulse Width ........................................................................................ 37
5.7 Pulse Integral ...................................................................................... 38
6. Verification .......................................................................................... 39
6.1 Histogram ........................................................................................... 39
6.2 Implementation ................................................................................... 40
7. Testing ................................................................................................. 43
7.1 Import data from Chipscope Pro™ to MATLAB® ........................... 43
7.2 Full Width at Half Maximum ............................................................. 44
7.3 Analysis .............................................................................................. 45
8. Results and Conclusion ....................................................................... 47
List of Papers ................................................................................................ 49
Abbreviations ................................................................................................ 53
1. Introduction
There exist various kinds of matter in this beautiful and mysterious world
and people began research for the ultimate constituents of matter centuries
ago. In the last fifty years, the Standard Model (SM) of particle physics was
formulated, which has assuredly succeeded in describing the fundamental
particles and their interactions. This theory divides the discovered matter
particles and force carriers into three categories as shown in Figure 1.1 [1].
The SM has been extensively tested by various experiments at high energies
and it has shown a remarkable predictive power which helped to observe yet
undiscovered particles.
The Large Hadron Collider (LHC at CERN in Switzerland) is expected to
address some of yet unsolved questions of the SM. It accelerates and collides
two beams of particles of the same kind [2]. Recently physicists have dis-
covered evidence of the Higgs boson predicted in SM. This particle is linked
to a mechanism that gives basic mass to elementary particles. It is close to
the SM Higgs boson but still much more data are required to prove all as-
pects of it [3].
Figure 1.1: Elementary particles of matter, force carriers and unproved Higgs bos-
on in the Standard Model [4].
1
The upcoming Anti-Proton Annihilation experiment called PANDA at the
Facility for Antiproton and Ion Research (FAIR) in Darmstadt Germany will
address yet unsolved questions of Quantum Chromo Dynamics (QCD) [5].
QCD is a main component of the SM together with the electroweak theory
and plays a key role in describing the interaction between the quarks [2].
PANDA will employ proton–antiproton annihilation to research the strong
interaction physics and particularly focus on undiscovered charmonium
states and exotic states such as charmed hybrids and glueballs [2, 5].
The PANDA experiment requires a multi-purpose detector with an important
component of a high resolution Electromagnetic Calorimeter (EMC) which
is applied to measure the energy of particles. The PANDA detector consists
of a target spectrometer (TS) and a forward spectrometer (FS). Those two
spectrometers allow the detector to cover a 4π solid angle and each of them
employs an EMC. A Shashlyk-type sampling calorimeter is employed as the
EMC in FS [2]. But especially the EMC in TS employs a fast scintillator
which is made of PbWO4 crystals, a high-density material suitable for stop-
ping high-energy particles and having a good energy resolution in photon
and electron detection [2, 6]. A three-dimensional illustration of the PAN-
DA detector including all sub-detectors is shown in Figure 1.2.

Target Spectrometer Forward Spectrometer

Figure 1.2: Overview of the PANDA detector including the sub-detector system [7].
The dynamic range of energy deposition aimed to be measured in individual
PbWO4 crystals is from 1 MeV up to 8 GeV. The crystals produce short
light pulses (20 ns signal rise-time) with intensity proportional to the energy
2